Free Sitemap Validator — Check a sitemap.xml for Errors
Paste your sitemap.xml and this free sitemap validator checks it against the rules Google actually enforces — valid XML, absolute URLs, the 50,000 URL / 50MB limits, and more. No signup, nothing leaves your browser.
Paste a sitemap to check it.
What This Checks
- Valid XML — the file must parse without errors; one malformed tag can make crawlers discard the whole file
- Correct root element — a
<urlset>(or<sitemapindex>for a sitemap of sitemaps) in the sitemaps.org namespace - Every
<url>has a<loc>— the one required child element - Absolute URLs — relative paths in
<loc>are invalid; every URL needs a full scheme and host - One consistent host — a sitemap should only list URLs from the domain (or subdomain) it's served from
- No duplicate URLs — the same
<loc>listed twice wastes crawl budget and can confuse priority signals - Size limits — a maximum of 50,000 URLs and 50MB uncompressed per sitemap file, per Google's sitemap protocol
- Valid
<lastmod>dates — when present, it should be a real W3C Datetime value, not a placeholder
Why a Sitemap Fails Silently
Google doesn't usually reject an invalid sitemap outright — it logs the error in Search Console's Sitemaps report and skips the broken entries, which means a typo or a relative URL can sit unnoticed for weeks while those pages simply never get crawled through that path. Running the raw file through a check like this before submitting it catches the structural problems a quick visual scan misses.
Sitemap Validator FAQs
Does a sitemap need a <lastmod> for every URL?
No, it's optional. When included, it should reflect a genuine last-modified date — Google's own guidance says it ignores lastmod values it doesn't trust, such as ones that update on every crawl regardless of real changes.
Can a sitemap mix URLs from different subdomains?
Only if the sitemap is hosted at a location that covers all of them (for example, served from the root domain with the right path setup) — by default, a sitemap can only include URLs that share its own host.
What happens if I go over 50,000 URLs?
Split the URLs across multiple sitemap files and list them all in a single sitemap index file — this tool flags the limit so you know when it's time to split.
Is a sitemap index file the same as a regular sitemap?
No — a sitemap index uses <sitemapindex> and <sitemap> elements pointing to other sitemap files, rather than <urlset> and <url> elements pointing to pages. This tool detects which type you've pasted.
Does this tool store or send my data anywhere?
No. Everything is checked in your browser with JavaScript — nothing is uploaded, logged, or stored on any server, including ours.
Need your sitemap fixed, not just flagged?
Contomatix handles technical SEO cleanup end to end, not just diagnostics.